Triethylamine → 1-(4-methoxybenzyl)-3-(3-nitrophenyl)-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole

Participants

Reaction Steps

1 g (2.3 mmol) of 4-iodo-1-(4-methoxybenzyl)-3-(3-nitrophenyl)-1H-pyrazole (prepared as described in Example 27) was dissolved in 20 ml of dry toluene and 3.18 ml of 4,4,5,5-tetramethyl-1,3,2-dioxaborolane (23 mmol), 20 mg (0.08 mmol) of palladium(II) chloride diacetonitrile complex, 80 mg (0.005 mmol) of S-Phos (2-dicyclohexylphosphino-2′,6′-dimethoxy-1,1′-biphenyl) and 774 μl (5.7 mmol) of triethylamine were added successively. The reaction mixture was submitted to microwave irradiation in a sealed vial at 90° C. for 30 minutes. The mixture was then filtered through a celite pad and the filtrate evaporated in vacuo. The residue was taken up with dichloromethane and washed with water and the organic layer dried over sodium sulphate and evaporated again. The crude was finally purified by flash-chromatography on a silica gel column (CH2Cl2-CH3COCH3 1%), affording 800 mg (80%) of the title compound, crystallized from diethylether.

Provenance & Evidence